PNP Fuzz Face w/ Charge Pump - Negative DC and Volume Isses

[standingzero]

Hey all,

Building a PNP Fuzz Face with a charge pump to allow for daisy chaining. When I test voltage on the designated pad (between C8 and the Collector of Q2) the voltage reads as Negative on my DMM. Is that normal?

Also, I barely reach unity gain when the voltage is in the recommended range of 4.6 - 4.8. What could I do to raise the amount of available voltage?

Thanks!

[Coda-effects]

Hello !

Fuzz face PNP fuzz face requires indeed a negative voltage to properly operate. The "charge pump" here is just a voltage inverter that provides the inverted voltage to the PNP transistors.

The loss of volume is a classical issue with fuzz face. I would recommend to change the bias of the second transistor in order to have more volume output. Replacing the 470R resistor (R3 here) with a bigger value like 1k, and replacing the bias resistor R6 by a bigger one too (some people uses 18K instead of 8.2k!) should help

Benoit

[standingzero]

Hello !

Fuzz face PNP fuzz face requires indeed a negative voltage to properly operate. The "charge pump" here is just a voltage inverter that provides the inverted voltage to the PNP transistors.

The loss of volume is a classical issue with fuzz face. I would recommend to change the bias of the second transistor in order to have more volume output. Replacing the 470R resistor (R3 here) with a bigger value like 1k, and replacing the bias resistor R6 by a bigger one too (some people uses 18K instead of 8.2k!) should help

Benoit

Thanks Benoit! Just to clarify, the reading on the DMM is SUPPOSED to be Negative. - Sorry, I just want to double check

I'll play with resistor values as recommended. Thanks a ton!